In 2002, a $7M grant was awarded to MBARI from the National Science Foundation to construct a deep-water test bed in Monterey Bay for the NEPTUNE cabled observatory. Additional funds were secured from the David and Lucile Packard Foundation ($1.8M) and from Canadian partners that were then part of the NEPTUNE team ($1.2M). A significant technological driver for the development of MARS was to design and implement high-power nodes for seafloor use.

MARS is now fully operational with 52 km of submarine cable and a node at 891 meters water depth (2,923 feet). Examples of science experiments on MARS include deployment of ORCA's Eye-in-the-Sea experiment to examine animals that thrive in the deep sea where sunlight does not penetrate; installation of a seafloor seismometer to study offshore earthquakes; and deployment of a benthic ROVER to investigate the carbon cycle at the seafloor-ocean interface. Expansion capabilites on this system allow scientists and researchers to take advantage of the real-time power and data transmission capabilities required to develop novel sensors for deployment in ocean environments.